When the Griswolds need to win their money back Mrs. Griswold gives Clark $2 and directs the family into the Luxor Casino (the giant lion-shaped building) to play Keno. When the old man next to them (played by Sid Ceasar) dies and drops his winning ticket on the floor Clark rescues the ticket from a passing vacuum cleaner. The side of the vacuum says MGM Grand but they walked into the Luxor.

Everyone is right.....they do go into the MGM Grand....the lion and the sphynx may look alike to some people. The lion isn't there anymore, it had been replaced with a larger lion statue standing up and a fountain.